(i) Field of the Invention
This invention relates to the connection of tubular tissue members, more especially blood vessels.
(ii) Description of the Prior Art
End-to-end connection of interrupted blood vessels in surgery is generally carried out by stitching with suture material.
Stitched connections are time consuming to complete, typically taking twenty minutes for each connection. While many surgeons have become adept in forming stitched connections, success is very much dependent on the skill of the individual surgeon.
The adaption of the operating microscope to the surgery of small vessels by Jacobson and Snarez in 1960 removed a barrier long believed insurmountable and showed that with intricate techniques and magnification successful suture anastomosis of vessels as small as 1 mm in diameter was possible.
Nevertheless, in spite of continuous training and the development of improved microscopes, instruments and sutures, many problems remain, and it remains difficult to obtain consistently high patency rates using suture techniques, particularly when dealing with vessels 1 to 2 mm in diameter.
The stitching of a connection between small diameter vessels in microsurgery presents special problems. The stitching operation is conducted under a microscope, often in a confined area.
Stitching also has the disadvantage that a foreign material, namely the suture is exposed at the interior blood contacting surface of the connection, and this presents a nidus for clot formation which in small vessel anastomosis is particularly likely to lend to occlusion. Proposals have been made for end-to-end stitchless connections, for example, in U.S. Pat. Nos. 3,155,095; 3,254,650; 3,254,651; 3,774,615 and 3,974,835. None of these prior proposals has proved to be practical and the prior devices have not been used in clinical applications.
In practice the handling and application of devices for stitchless connections is difficult. The devices are necessarily small in size since typically the vessels being connected have diameters in the range of 0.75 mm to 7.5 mm, and the vessel must not be unduly stretched.
It is extremely important that connections between blood vessels be complete and free of leaks. Failure of the connection results in internal bleeding which may be fatal.
There has been no previous proposal for an end-to-side non-suture anastomosis.
Stitchless connections provide the possibility of completing anastomosis in a much shorter time, more simply, while at the same time avoiding the presence of foreign material at the internal blood contacting surface of the connection.